Highlanders With High Altitude Pulmonary Hypertension (HAPH), Pulmonary Arterial Pressure (PAP) Assessed at 3200m With and Without Supplemental Oxygen Therapy (SOT)

Effect of Supplemental Oxygen Therapy (SOT) on Pulmonary Arterial Pressure in Highlanders With High Altitude Pulmonary Hypertension Permanently Living at >2500m

The investigators aim to study the effect of SOT in highlanders with high altitude pulmonary hypertension (HAPH) who permanently live >2500m on pulmonary arterial pressure (PAP) assessed at 3200 m.

Highlanders with HAPH diagnosed by echocardiography and defined by a RV/RA (Tricuspid Regurgitation Pressure Gradient) >30 mmHg will be recruited for this project. Highlanders permanently living at HA >2500 m will have echocardiografy to assess PAP near their living altitude in Aksay at 3200 m with and without 10L/min supplemental oxygen therapy (SOT) via face mask.

Inclusion Criteria:

• Permanently living >2500 m
• HAPH diagnosed with a minimum RV/RA of 30 mmHg assessed by echocardiography at an altitude of 3200 m
• Written informed consent

Exclusion Criteria:

• Highlanders who cannot follow the study investigations,
• Patients with moderate to severe concomitant lung disease (FEV1<70% or forced vital capacity <70%), severe parenchymal lung disease, heavy smoking >20 cigarettes/day or >20 pack-years.
• Coexistent unstable systemic hypertension or coronary artery disease that required adjustment of medication within the last 2 months
• Regular use of medication that affects control of breathing (benzodiazepines, opioids, acetazolamide)